It is well known that wearable light devices have advantages over handheld flashlights for night-time activities. A wearable light device leaves both hands free for carrying articles or doing other work, or for simply swinging naturally while running or walking. A light worn on the forehead has the further advantage of illuminating the center of the wearer's field of vision.
A familiar disadvantage of forehead-worn light devices is that, because the main light beam is emitted largely parallel to the direction of gaze, looking toward a reflective surface causes the beam to be reflected directly back into the wearer's eyes. Such reflective surfaces include windows and mirrors, shiny metal surfaces, water, and snow.
To ameliorate this problem, some forehead-worn light devices can switch between two intensity levels of emitted light. Thus, someone wearing a forehead lighting device could switch it to the lower intensity level before leaning over to examine his ski bindings, for example, to avoid being dazzled by reflection from the snow surface. Two intensity levels do not, however, protect a wearer whose gaze unexpectedly crosses a reflective surface, or who forgets to switch levels before looking toward one.
Another familiar disadvantage of forehead-worn lighting devices is the problem of dazzling other persons by looking toward them with the light illuminated. Again, two-levels of light intensity can ameliorate the problem, but only if the wearer remembers to operate the switch before looking at the other person. Even so, the low intensity level may be bright enough to cause a dark-adapted person discomfort and spoil their vision for many minutes.
A wearable lighting device that is useful for high speed sports, such as surfing or skiing, or for seeing long distances, such as route finding while orienteering or rock climbing in darkness or twilight, must emit especially intense light. The bright beam needed for such activities makes the problem of accidentally blinding oneself or others more serious.
There is a long-felt need for a wearable light device that can emit enough light to perform activities normally restricted to either the day time, or to locations with bright artificial lighting, while avoiding the blinding reflective or incident light that is often associated with such lighting devices.